Among viruses, human immunodeficiency virus (HIV), a kind of retrovirus, is known to cause acquired immunodleficiency syndrome (AIDS). The drug for treatment of AIDS is mainly selected from the group of reverse transcriptase inhibitors (AZT, 3TC, and the like) and protease inhibitors (Indinavir and the like), but they are proved to be accompanied by side effects such as nephropathy and the emergence of resistant virus. Thus, the development of anti-HIV drugs having the other mechanism of action has been desired.
In the above circumstance, integrase has recently been thought to be noteworthy, which is an enzyme relating to the site-specific insertion of viral DNA into chromosome in animal cells, and the research for anti-HIV drugs based on said enzyme inhibition activity is performed ((1) Proc. Natl. Acad. Sci. USA 61 (3), 1013-1020 (1968), KOURILSKY P et al.; (2) J. VIROL. METHODS (NETHERLANDS), 17/1-2(55-61) (1987), F Barin et al.; (3) Proc. Natl. Acad. Sci. USA 90: 2399 (1993), Fesen. MR (1993); (4) CDC AIDS Weekly Pagination:P2 (1990). DeNoon, D J). Some integrase inhibitors has recently been reported, for example, peptide derivatives described in U.S. Pat. No. 5,578,573, tetrahydronaphthyl derivatives described in GB 2306476A, and acrydone derivatives described in WO 97/38999.
Additionally, in the literature, Khim. Geterotsikl. Soedin. 1973, (11), 1519, some kind of indole derivatives are described, but their therapeutic activity is not described. Moreover, in U.S. Pat. No. 5.475,109, non-condensed heterocyclic compounds substituted with dioxobutanoic acid are described to be useful as an anti influenza viral drug, whose mechanism of the action is the inhibition of cap-dependent endonuclease.